Refuse chain rollback past a checkpoint

src/db/storage.cpp

@@ -1421,6 +1421,10 @@ namespace db
     MONERO_PRECOND(!hashes.empty());
     MONERO_PRECOND(db != nullptr);
 
+    // refuse to rollback past a checkpoint
+    if (height < block_id(get_checkpoints().get_max_height()))
+      return {lws::error::bad_blockchain};
+
     return db->try_write([this, height, hashes] (MDB_txn& txn) -> expect<void>
     {
       cursor::blocks blocks_cur;

tests/unit/db/chain.test.cpp

@@ -28,6 +28,8 @@
 #include "chain.test.h"
 
 #include <cstdint>
+#include "checkpoints/checkpoints.h" // monero/src
+#include "config.h"
 #include "db/storage.test.h"
 #include "error.h"
 
@@ -112,6 +114,26 @@ LWS_CASE("db::storage::sync_chain")
       lws_test::test_chain(lest_env, MONERO_UNWRAP(db.start_read()), last_block.id, fchain);
       EXPECT(get_account().scan_height == lws::db::block_id(std::uint64_t(last_block.id) + 1));
     }
+
+    SECTION("Fork past checkpoint")
+    {
+      cryptonote::checkpoints checkpoints;
+      checkpoints.init_default_checkpoints(lws::config::network);
+
+      const auto& points = checkpoints.get_points();
+      EXPECT(3 <= points.size());
+
+      auto point = ++points.begin();
+
+      const crypto::hash fchain[3] = {
+        point->second,
+        crypto::rand<crypto::hash>(),
+        crypto::rand<crypto::hash>()
+      };
+
+      const auto sync_result = db.sync_chain(lws::db::block_id(point->first), fchain);
+      EXPECT(sync_result == lws::error::bad_blockchain);
+    }
   }
 }
 

tests/unit/scanner.test.cpp

@@ -282,8 +282,6 @@ namespace
 
 LWS_CASE("lws::scanner::sync and lws::scanner::run")
 {
-   mlog_set_log_level(4);
-
   cryptonote::account_keys keys{};
   crypto::generate_keys(keys.m_account_address.m_spend_public_key, keys.m_spend_secret_key);
   crypto::generate_keys(keys.m_account_address.m_view_public_key, keys.m_view_secret_key);